feat: remove previous back button and add a switching validate/back button for better UX

LICENCE

@@ -0,0 +1,5 @@
+Ce travail est mis à disposition selon les termes de la Licence Creative Commons Attribution - Pas d'Utilisation Commerciale - Partage dans les Mêmes Conditions 4.0 International.
+
+Pour voir une copie de cette licence, visitez : http://creativecommons.org/licenses/by-nc-sa/4.0/
+
+Auteur : Lucas Royer pour L'Atelier du Pignon (Nantes) 

Readme.md

@@ -0,0 +1,39 @@
+# stock-pignon 🚲
+
+Application Android (4.2+) de gestion de stock et d'aide à la vente à prix libre. Conçue pour l'[**Atelier du Pignon**](https://www.atelierdupignon.fr/), atelier d'auto-réparation à Nantes.
+
+![Pignon1](https://github.com/user-attachments/assets/1e43e8f2-872c-41c2-9e12-405e41db5ca1)
+
+## 🛠 Fonctionnalités
+- **Catalogue visuel** : Permet aux adhérent·es de noter rapidement les pièces qu'iels ont emportées.
+- **Prix libre & conscient** : Calculateur de panier affichant une fourchette de prix suggérée.
+- **Clé en main** : Par défaut, l'application installera un catalogue par défaut, utilisable tout de suite pour un atelier d'autoréparation de vélo.
+- **Modulable** : Le catalogue de pièces peut-être modifié sans connaissance informatique préalable et sans recompilation de l'application, via un fichier JSON en entrée et un dossier d'images.
+- **Traçabilité** : Les quantités emportées est consignée dans un fichier JSON en sortie.
+- **Réemploi** : L'application a été développé pour réutiliser de vieilles tablettes Android laissées à l'abandon. Ainsi, la compatibilité est assurée pour les versions Android Jelly Bean 4.2 et supérieures.
+
+## ⚠️Avertissement
+- Cette application a été développée pour fonctionner uniquement avec la tablette **Acer Iconia A3-A10**.
+- L'application devrait fonctionner sur une tablette similaire : Android 4.2 ou supérieur + écran équivalent (10.1" - 1280 x 800). Cela n'a cependant pas encore été testé.
+
+## 📱 Utilisation
+1. [Télécharger l'APK](https://github.com/lucasroyerdev/stock-pignon/releases/tag/v0.1.0) sur la tablette et installer.
+2. À la première utilisation, un dossier contenant un dossier d'exemple `stock_pignon` est créé dans la mémoire interne.
+3. Si vous souhaitez modifier les objets présentés, vous pouvez modifier `stock_pignon/pieces.json` ainsi que les images dans le dossier `stock_pignon/images`.
+4. Après la validation du premier panier, un fichier `stock_pignon/stock.json` sera créé afin de comptabiliser les pièces emportées.
+
+## 💻 Développement
+- **Langage** : Java 8 (Android Natif)
+- **SDK Android** : API 17 (Android 4.2 Jelly Bean)
+- **Environnement** : Android Studio Otter | 2025.2.1 Patch 1
+
+## ⚖️ Licence
+
+Ce projet est sous licence **CC BY-NC-SA 4.0**.  
+Cela signifie que vous êtes libre de partager et d'adapter le code, tant que vous citez l'auteur original, que vous n'en faites pas un usage commercial, et que vous diffusez vos modifications sous la même licence.
+
+## 👀 Screenshots
+![Pignon2](https://github.com/user-attachments/assets/78439dff-cde4-4d75-8a8f-f6ee38a69abf)
+![Pignon3](https://github.com/user-attachments/assets/51694675-ec5f-4a59-95a9-7b7e0dd1caf3)
+![Pignon4](https://github.com/user-attachments/assets/f402250c-045c-4b3d-bbdc-11ae22bd62b2)
+

app/build.gradle

@@ -10,8 +10,8 @@ android {
         applicationId "com.stock.pignon"
         minSdkVersion 17
         targetSdkVersion 36
-        versionCode 1
+        versionCode 5
-        versionName "1.0"
+        versionName "0.5.0"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -41,6 +41,9 @@ dependencies {
     // GIF
     implementation 'com.github.bumptech.glide:glide:3.8.0'
 
+    // NanoHTTPD
+    implementation 'org.nanohttpd:nanohttpd:2.3.1'
+
     // Tests
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'

app/src/main/AndroidManifest.xml

@@ -4,6 +4,8 @@
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
 
     <application
         android:allowBackup="true"

app/src/main/java/com/stock/pignon/CartActionHelper.java

@@ -3,7 +3,6 @@ package com.stock.pignon;
 
 import android.app.AlertDialog;
 import android.content.Context;
-import android.content.Intent;
 import android.os.Handler;
 import android.os.Environment;
 import android.text.Html;
@@ -12,7 +11,6 @@ import android.view.View;
 import android.widget.GridLayout;
 import android.widget.LinearLayout;
 import android.widget.TextView;
-import android.widget.ImageView;
 
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
@@ -23,11 +21,8 @@ import java.io.FileOutputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
 import java.lang.reflect.Type;
-import java.util.HashMap;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
-
-import com.bumptech.glide.Glide;
 
 /**
  * Action on shopping cart: validation, clearing, and persistence
@@ -36,6 +31,21 @@ public class CartActionHelper {
 
     private static final String TAG = "CartActionHelper";
 
+    /**
+     * Data structure for JSON and CSV
+     */
+    private static class StockEntry {
+        String date;
+        String name;
+        int qty;
+
+        StockEntry(String date, String name, int qty) {
+            this.date = date;
+            this.name = name;
+            this.qty = qty;
+        }
+    }
+
     /**
      * Resets the cart data and refreshes UI
      */
@@ -93,6 +103,74 @@ public class CartActionHelper {
                 .show();
     }
 
+
+
+    /**
+     * Merges current cart items with the existing stock file (json and csv) on the SD Card.
+     */
+    private static void saveCartToExternalFile(List<CartItem> cartItems) {
+        File dir = new File(Environment.getExternalStorageDirectory(), Config.EXTERNAL_DIR_NAME);
+        File stockFile = new File(dir, Config.OUTPUT_JSON_NAME);
+        File csvFile = new File(dir, Config.OUTPUT_CSV_NAME);
+
+        String today = DateHelper.getTodayIso();
+        Gson gson = new Gson();
+
+        // Load previous list
+        List<StockEntry> history = loadHistory(stockFile, gson);
+
+        // Merge current cart items in previous list
+        for (CartItem cartItem : cartItems) {
+            boolean merged = false;
+            for (StockEntry entry : history) {
+                // Same date same name ? Add it
+                if (entry.date.equals(today) && entry.name.equals(cartItem.getName())) {
+                    entry.qty += cartItem.getQuantity();
+                    merged = true;
+                    break;
+                }
+            }
+            // Not found on the same date ? Create it
+            if (!merged) {
+                history.add(new StockEntry(today, cartItem.getName(), cartItem.getQuantity()));
+            }
+        }
+        // Save to JSON
+        try (FileOutputStream fos = new FileOutputStream(stockFile);
+             OutputStreamWriter writer = new OutputStreamWriter(fos, "UTF-8")) {
+            gson.newBuilder().setPrettyPrinting().create().toJson(history, writer);
+        } catch (Exception e) {
+            Log.e(TAG, "Error writing JSON", e);
+        }
+
+        // Save to CSV, french format with ";"
+        try (FileOutputStream fos = new FileOutputStream(csvFile);
+             OutputStreamWriter writer = new OutputStreamWriter(fos, "UTF-8")) {
+            writer.write('\ufeff');
+            writer.write("Date;Article;Quantité\n");
+            for (StockEntry entry : history) {
+                writer.write(entry.date + ";" + entry.name.replace(";", ",") + ";" + entry.qty + "\n");
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "Error writing CSV", e);
+        }
+    }
+
+    /**
+     * Load JSON history
+     */
+    private static List<StockEntry> loadHistory(File file, Gson gson) {
+        if (!file.exists()) return new ArrayList<>();
+        try (InputStreamReader reader = new InputStreamReader(new FileInputStream(file), "UTF-8")) {
+            Type type = new TypeToken<List<StockEntry>>(){}.getType();
+            List<StockEntry> result = gson.fromJson(reader, type);
+            return (result != null) ? result : new ArrayList<>();
+        } catch (Exception e) {
+            Log.e(TAG, "Error reading json history", e);
+            return new ArrayList<>();
+        }
+    }
+
     /**
      * Displays a thank you popup and returns to the main menu after 2 seconds.
      */
@@ -104,78 +182,21 @@ public class CartActionHelper {
                 .create();
         merciDialog.show();
 
-
         new Handler().postDelayed(() -> {
             // Close dialog
             merciDialog.dismiss();
+
+            if (activity instanceof MainActivity) {
+                MainActivity main = (MainActivity) activity;
                 // Go to home if not already
-            if (!(activity instanceof MainActivity)) {
+                main.showHome();
-                Intent intent = new Intent(activity, MainActivity.class);
                 // Clear the backstack so the user can't "go back" to a validated cart
-                intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
+                GridLayout grid = main.findViewById(R.id.gridPieces);
-                activity.startActivity(intent);
+                refreshGridQuantities(grid);
             }
         }, 2000);
     }
 
-    /**
-     * Merges current cart items with the existing stock file on the SD Card.
-     */
-    private static void saveCartToExternalFile(List<CartItem> cartItems) {
-        File stockFile = new File(Environment.getExternalStorageDirectory(), Config.STOCK_FILE_NAME);
-        Gson gson = new Gson();
-        Map<String, Integer> stockMap;
-
-        // Load data into a Map (Key: Item Name, Value: Total Quantity)
-        stockMap = loadExistingStock(stockFile, gson);
-
-        // Merge with new items from current cart
-        for (CartItem item : cartItems) {
-            // Get previous quantity
-            Integer qtyObj = stockMap.get(item.getName());
-            int currentQty = (qtyObj != null) ? qtyObj : 0;
-            // Add
-            stockMap.put(item.getName(), currentQty + item.getQuantity());
-        }
-
-        // Overwrite the file with updated data
-        // Needs WRITE_EXTERNAL_STORAGE permission
-        try (FileOutputStream fos = new FileOutputStream(stockFile);
-             @SuppressWarnings("CharsetObjectCanBeUsed")
-             OutputStreamWriter writer = new OutputStreamWriter(fos, "UTF-8")) {
-
-            // Writing directly to the stream
-            gson.toJson(stockMap, writer);
-            Log.i(TAG, "Stock updated successfully at: " + stockFile.getAbsolutePath());
-
-        } catch (Exception e) {
-            Log.e(TAG, "Failed to write stock file", e);
-        }
-    }
-
-    /**
-     * Reads the current stock file. If the file is missing or corrupted, returns an empty map.
-     */
-    private static Map<String, Integer> loadExistingStock(File stockFile, Gson gson) {
-        if (!stockFile.exists()) return new HashMap<>();
-
-        try (FileInputStream fis = new FileInputStream(stockFile);
-             @SuppressWarnings("CharsetObjectCanBeUsed")
-             InputStreamReader reader = new InputStreamReader(fis, "UTF-8")) {
-
-            // Type definition for Map required by GSON : <String, Integer>
-            Type type = new TypeToken<Map<String, Integer>>(){}.getType();
-            // Read and fill map
-            Map<String, Integer> result = gson.fromJson(reader, type);
-
-            return (result != null) ? result : new HashMap<>();
-
-        } catch (Exception e) {
-            Log.e(TAG, "Error reading existing stock, starting fresh", e);
-            return new HashMap<>();
-        }
-    }
-
     /**
      * Updates the UI grid to reflect quantities.
      */

app/src/main/java/com/stock/pignon/CartViewHelper.java

@@ -22,17 +22,23 @@ import java.util.List;
 public class CartViewHelper {
 
     /**
-     * Refreshes the entire cart side-panel or list
+     * Short version for app resume : update without changing validate/back button state
-     * Clears everything and rebuild on current CartManager data
      */
     public static void updateCartView(LinearLayout cartList, Context context) {
+        updateCartView(cartList, context, false, false);
+    }
+
+    /**
+     * Full version with validate/back button management
+     */
+    public static void updateCartView(LinearLayout cartList, Context context, boolean updateButton, boolean isHome) {
         if (cartList == null) return;
 
-        // Clear and get current items
+        // Clean item lists
         cartList.removeAllViews();
         List<CartItem> cartItems = CartManager.getItems();
 
-        // If empty cart, show it to user
+        // Manage empty cart
         if (cartItems.isEmpty()) {
             TextView empty = new TextView(context);
             empty.setText(context.getString(R.string.cart_empty));
@@ -40,35 +46,24 @@ public class CartViewHelper {
             empty.setGravity(Gravity.CENTER);
             empty.setPadding(0, 50, 0, 0);
             cartList.addView(empty);
-
             updateTotalDisplay(context, 0, 0);
-            return;
+        } else {
-        }
+            // Create list if not empty
-
-        // Build list and calculate total at the same time
             int totalMin = 0;
             int totalMax = 0;
-
             for (CartItem item : cartItems) {
                 totalMin += item.getTotalMin();
                 totalMax += item.getTotalMax();
 
-            // Create and add the row view
+                // Create a line for each item
                 cartList.addView(createCartItemView(item, cartList, context));
             }
-
-        // Display global price range at the end
             updateTotalDisplay(context, totalMin, totalMax);
         }
 
-    /**
+        // Update validate/back button
-     * Updates the global price range at the bottom of the screen
+        if (updateButton && context instanceof MainActivity) {
-     */
+            ((MainActivity) context).updateActionButton(isHome);
-    private static void updateTotalDisplay(Context context, int min, int max) {
-        TextView totalView = ((Activity) context).findViewById(R.id.totalView);
-        if (totalView != null) {
-            // Using string resources
-            totalView.setText(context.getString(R.string.price_range, min, max, "€"));
         }
     }
 
@@ -81,7 +76,6 @@ public class CartViewHelper {
         row.setOrientation(LinearLayout.HORIZONTAL);
         row.setGravity(Gravity.CENTER_VERTICAL);
 
-        // Layout parameters
         LinearLayout.LayoutParams rowParams = new LinearLayout.LayoutParams(
                 LinearLayout.LayoutParams.MATCH_PARENT,
                 LinearLayout.LayoutParams.WRAP_CONTENT);
@@ -90,13 +84,13 @@ public class CartViewHelper {
 
         // Image
         ImageView image = new ImageView(context);
-        ImageLoader.loadImage(image, item.getImageFile(),200,200);
+        ImageLoader.loadImage(image, item.getImageFile(), 200, 200);
         LinearLayout.LayoutParams imgParams = new LinearLayout.LayoutParams(100, 100);
         imgParams.setMargins(0, 0, 20, 0);
         image.setLayoutParams(imgParams);
         row.addView(image);
 
-        // Sublayout for name + [quantity + price]
+        // Sublayout infos
         LinearLayout infoLayout = new LinearLayout(context);
         infoLayout.setOrientation(LinearLayout.VERTICAL);
         infoLayout.setLayoutParams(new LinearLayout.LayoutParams(0, LinearLayout.LayoutParams.WRAP_CONTENT, 1f));
@@ -108,7 +102,7 @@ public class CartViewHelper {
         nameView.setTypeface(null, Typeface.BOLD);
         infoLayout.addView(nameView);
 
-        // Quantity and price range
+        // Quantity / price
         TextView detailsView = new TextView(context);
         String details = context.getString(R.string.cart_item, item.getQuantity(), item.getTotalMin(), item.getTotalMax());
         detailsView.setText(details);
@@ -124,42 +118,35 @@ public class CartViewHelper {
     }
 
     /**
-     * Creates the delete button
+     * Creates the delete button for each item
     */
     private static Button createRemoveButton(CartItem item, LinearLayout cartList, Context context) {
         Button btn = new Button(context);
         btn.setText("✖");
-        btn.setTextSize(18);
         btn.setTextColor(Color.WHITE);
-        btn.setGravity(Gravity.CENTER);
-
-        // Conversion DP to PX for consistent size on all screens
         float scale = context.getResources().getDisplayMetrics().density;
         int sizePx = (int) (48 * scale + 0.5f);
+        btn.setLayoutParams(new LinearLayout.LayoutParams(sizePx, sizePx));
 
-        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(sizePx, sizePx);
-        btn.setLayoutParams(params);
-
-        // Background: grey rounded rectangle (API 17 fallback)
         GradientDrawable shape = new GradientDrawable();
-        shape.setColor(Color.parseColor("#E53935")); // Reddish to indicate delete
+        shape.setColor(Color.parseColor("#E53935"));
         shape.setCornerRadius(4 * scale);
         btn.setBackground(shape);
 
         btn.setOnClickListener(v -> {
-            // setting quantity to 0 removes the item
+            CartManager.addOrUpdateItem(item.getName(), item.getMinPrice(), item.getMaxPrice(), 0, item.getImageFile());
-            CartManager.addOrUpdateItem(
-                    item.getName(),
-                    item.getMinPrice(),
-                    item.getMaxPrice(),
-                    0, // Setting quantity to 0 triggers removal
-                    item.getImageFile()
-            );
-
-            // visual refresh of the cart list
             updateCartView(cartList, context);
         });
-
         return btn;
     }
+
+    /**
+     * Manage price range for whole cart
+     */
+    private static void updateTotalDisplay(Context context, int min, int max) {
+        TextView totalView = ((Activity) context).findViewById(R.id.totalView);
+        if (totalView != null) {
+            totalView.setText(context.getString(R.string.price_range, min, max, "€"));
+        }
+    }
 }

app/src/main/java/com/stock/pignon/Config.java

@@ -9,8 +9,11 @@ public class Config {
     public static final String IMAGES_SUBDIR_NAME = "images";
 
     // Input json
-    public static final String PIECES_FILE_NAME = "pieces.json";
+    public static final String INPUT_JSON_NAME = "pieces.json";
 
     // Output json
-    public static final String STOCK_FILE_NAME = "stock.json";
+    public static final String OUTPUT_JSON_NAME = "stock.json";
+
+    // Output json
+    public static final String OUTPUT_CSV_NAME = "stock.csv";
 }

app/src/main/java/com/stock/pignon/ControlServer.java

@@ -0,0 +1,254 @@
+// ControlServer.java
+package com.stock.pignon;
+
+import android.os.Environment;
+
+import fi.iki.elonen.NanoHTTPD;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.List;
+
+/**
+ * Create a web server to remote management of app assets.
+ */
+// Inherit what is needed to build a web server
+public class ControlServer extends NanoHTTPD {
+
+    // Assets folders
+    private final File storageRoot = Environment.getExternalStorageDirectory();
+    private final File baseDir = new File(storageRoot, Config.EXTERNAL_DIR_NAME);
+    private final File imagesDir = new File(baseDir, Config.IMAGES_SUBDIR_NAME);
+
+    public ControlServer(int port) {
+        super(port);
+    }
+
+    /**
+     * Main method which receive remote request
+     */
+    @Override
+    public Response serve(IHTTPSession session) {
+        // Get requested address
+        String uri = session.getUri();
+
+        switch (uri) {
+            case "/download_input":
+                return downloadFile(Config.INPUT_JSON_NAME);
+
+            case "/output_json":
+                return viewFile(Config.OUTPUT_JSON_NAME);
+
+            case "/download_output_json":
+                return downloadFile(Config.OUTPUT_JSON_NAME);
+
+            case "/output_csv":
+                return viewFile(Config.OUTPUT_CSV_NAME);
+
+            case "/download_output_csv":
+                return downloadFile(Config.OUTPUT_CSV_NAME);
+
+            case "/":
+            case "/index.html":
+                return newFixedLengthResponse(getHtmlResponse());
+        }
+
+        // File upload management
+        if (session.getMethod() == Method.POST) {
+            if (uri.equals("/upload_json")) {
+                return handleJsonUpload(session);
+            } else if (uri.equals("/upload_images")) {
+                return handleImagesUpload(session);
+            }
+        }
+
+        return newFixedLengthResponse(Response.Status.NOT_FOUND, MIME_PLAINTEXT, "❌ Page non trouvée");
+    }
+
+    /**
+     * HTML UI for users
+     */
+    private String getHtmlResponse() {
+        return "<html>" +
+                "<head>" +
+                "<meta charset='UTF-8'>" +
+                "<meta name='viewport' content='width=device-width, initial-scale=1'>" +
+                "<style>" +
+                "body { font-family: sans-serif; line-height: 1.6; padding: 20px; color: #333; max-width: 800px; margin: auto; }" +
+                "h1 { color: #0049AF; border-bottom: 2px solid #0049AF; }" +
+                "h2 { color: #555; margin-top: 30px; }" +
+                ".card { background: #f4f4f4; padding: 15px; border-radius: 8px; margin-bottom: 20px; border: 1px solid #ddd; }" +
+                ".btn { display: inline-block; width: 280px; height: 45px; line-height: 45px; text-align: center; background: #0049AF; color: white; text-decoration: none; border-radius: 4px; border: none; cursor: pointer; font-weight: bold; box-sizing: border-box; padding: 0; -webkit-appearance: none; font-family: inherit; font-size: 14px; font-style: normal; letter-spacing: normal; margin: 10px 5px; vertical-align: middle;}" +
+                ".btn-download { background: #2E7D32; }" +
+                "input[type='file'] { margin: 10px 0; }" +
+                ".status { font-weight: bold; color: green; }" +
+                "</style>" +
+                "</head>" +
+                "<body>" +
+                "<h1>Application : stock-pignon</h1>" +
+
+                "<h2>Gestion des stocks</h2>" +
+                "<div class='card'>" +
+                "<h3>Récupérer les sacoches des adhérent·es</h3>" +
+                "<p>Télécharger le décompte des pièces sorties de l'atelier.</p>" +
+                "<a href='/output_json' class='btn'>Voir stock.json</a>" +
+                "<a href='/output_csv' class='btn'>Voir stock.csv</a>" +
+                "<a href='/download_output_json' class='btn'>Télécharger stock.json</a>" +
+                "<a href='/download_output_csv' class='btn'>Télécharger stock.csv</a>" +
+                "</div>" +
+
+                "<h2>Modifier le catalogue</h2>" +
+                "<div class='card'>" +
+                "<h3>Gestion du fichier JSON</h3>" +
+                "<p>Catalogue actuel : <a href='/download_input' class='btn'>Télécharger pieces.json</a></p>" +
+                "<hr>" +
+                "<form action='/upload_json' method='post' enctype='multipart/form-data'>" +
+                "<p><strong>Envoyer un nouveau catalogue :</strong></p>" +
+                "<input type='file' name='json_file' accept='.json'><br>" +
+                "<input type='submit' value='Remplacer pieces.json' class='btn'>" +
+                "</form>" +
+                "</div>" +
+
+                "<div class='card'>" +
+                "<h3>Gestion des images</h3>" +
+                "<form action='/upload_images' method='post' enctype='multipart/form-data'>" +
+                "<p><strong>Ajouter/Modifier des images (PNG/JPG) :</strong></p>" +
+                "<input type='file' name='images' accept='image/*' multiple><br>" +
+                "<input type='submit' value='Envoyer les images' class='btn'>" +
+                "</form>" +
+                "</div>" +
+
+                "</body>" +
+                "</html>";
+    }
+
+    /**
+     * Manage JSON sent by remote.
+     */
+    private Response handleJsonUpload(IHTTPSession session) {
+        Map<String, String> tmpFiles = new HashMap<>();
+        try {
+            session.parseBody(tmpFiles);
+            // NanoHTTPD stocke le fichier avec le nom du champ HTML (json_file)
+            String tmpPath = tmpFiles.get("json_file");
+            if (tmpPath == null) return newFixedLengthResponse("❌ Aucun fichier reçu.");
+
+            File src = new File(tmpPath);
+            File dest = new File(baseDir, Config.INPUT_JSON_NAME);
+
+            copyFile(src, dest);
+            return newFixedLengthResponse("✅ Catalogue mis à jour ! <a href='/'>Retour</a>");
+        } catch (Exception e) {
+            return newFixedLengthResponse("❌ Erreur JSON : " + e.getMessage());
+        }
+    }
+
+    /**
+     * Manage multiple images sent by remote.
+     */
+    private Response handleImagesUpload(IHTTPSession session) {
+        Map<String, String> tmpFiles = new HashMap<>();
+        try {
+            session.parseBody(tmpFiles);
+
+            if (!imagesDir.exists() && !imagesDir.mkdirs()) {
+                return newFixedLengthResponse(Response.Status.INTERNAL_ERROR, MIME_PLAINTEXT,
+                        "❌ Erreur : Impossible de créer le dossier des images sur la tablette.");
+            }
+
+            int count = 0;
+
+            // On parcourt les fichiers temporaires créés par NanoHTTPD
+            for (Map.Entry<String, String> entry : tmpFiles.entrySet()) {
+                // NanoHTTPD indexe les envois multiples (images, images1, images2...)
+                if (entry.getKey().startsWith("images")) {
+                    String tmpPath = entry.getValue();
+
+                    // Récupération sécurisée des paramètres pour obtenir le nom original
+                    List<String> params = session.getParameters().get(entry.getKey());
+
+                    if (params != null && !params.isEmpty()) {
+                        // Nettoyage du nom de fichier (pour ne garder que "image.jpg" sans le chemin PC)
+                        String originalName = new File(params.get(0)).getName();
+
+                        File src = new File(tmpPath);
+                        File dest = new File(imagesDir, originalName);
+
+                        copyFile(src, dest);
+                        count++;
+                    }
+                }
+            }
+
+            return newFixedLengthResponse("✅ " + count + " images enregistrées ! <a href='/'>Retour</a>");
+
+        } catch (Exception e) {
+            return newFixedLengthResponse(Response.Status.INTERNAL_ERROR, MIME_PLAINTEXT,
+                    "❌ Erreur serveur : " + e.getMessage());
+        }
+    }
+
+    /**
+     * Prepare file and offer as download
+     */
+    private Response downloadFile(String filename) {
+        File file = new File(baseDir, filename);
+        if (!file.exists()) {
+            return newFixedLengthResponse(Response.Status.NOT_FOUND, MIME_PLAINTEXT, "❌ Fichier non trouvé.");
+        }
+        try {
+            InputStream is = new FileInputStream(file);
+
+            // Force download
+            Response res = newChunkedResponse(Response.Status.OK, "application/octet-stream", is);
+
+            res.addHeader("Content-Disposition", "attachment; filename=\"" + filename + "\"");
+            return res;
+        } catch (IOException e) {
+            return newFixedLengthResponse("❌ Erreur de lecture.");
+        }
+    }
+
+    /**
+     * Prepare file and print it in browser
+     */
+    private Response viewFile(String filename) {
+        File file = new File(baseDir, filename);
+        if (!file.exists()) {
+            return newFixedLengthResponse(Response.Status.NOT_FOUND, MIME_PLAINTEXT, "❌ Fichier non trouvé.");
+        }
+        try {
+            InputStream is = new FileInputStream(file);
+
+            // Force Mime type to print file inside browser
+            String mimeType = "text/plain";
+
+            Response res = newChunkedResponse(Response.Status.OK, mimeType + "; charset=utf-8", is);
+
+            res.addHeader("Content-Disposition", "inline");
+            return res;
+        } catch (IOException e) {
+            return newFixedLengthResponse("❌ Erreur de lecture.");
+        }
+    }
+
+    /**
+     * Utility method to copy file byte per byte.
+     * Not always possible to simply move a file on Android.
+     */
+    private void copyFile(File src, File dst) throws IOException {
+        try (InputStream in = new FileInputStream(src);
+             OutputStream out = new FileOutputStream(dst)) {
+            byte[] buf = new byte[1024];
+            int len;
+            while ((len = in.read(buf)) > 0) {
+                out.write(buf, 0, len);
+            }
+        }
+    }
+}

app/src/main/java/com/stock/pignon/DataLoader.java

@@ -13,7 +13,7 @@ import java.util.List;
 public class DataLoader {
     private static final String TAG = "DataLoader"; // For readable logs
     private static final String EXTERNAL_DIR = Config.EXTERNAL_DIR_NAME;
-    private static final String PIECES_FILE = Config.PIECES_FILE_NAME;
+    private static final String PIECES_FILE = Config.INPUT_JSON_NAME;
 
     // Raw data
     private static List<Category> cachedCategories = new ArrayList<>();

app/src/main/java/com/stock/pignon/DateHelper.java

@@ -0,0 +1,15 @@
+// DateHelper.java
+package com.stock.pignon;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Locale;
+
+public class DateHelper {
+    /**
+     * Return ISO format date (AAAA-MM-JJ)
+     */
+    public static String getTodayIso() {
+        return new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(new Date());
+    }
+}

app/src/main/java/com/stock/pignon/MainActivity.java

@@ -1,3 +1,4 @@
+// MainActivity.java
 package com.stock.pignon;
 
 import android.graphics.Color;
@@ -31,7 +32,7 @@ public class MainActivity extends AppCompatActivity {
 
     private static final String TAG = "MainActivity";
 
-    // UI Components
+    // UI components
     private LinearLayout cartList;
     private LinearLayout homeLayout;
     private LinearLayout categoryItemsLayout;
@@ -39,6 +40,9 @@ public class MainActivity extends AppCompatActivity {
     private GridLayout gridPieces;
     private ImageView mainImage;
 
+    // Server component
+    private ControlServer server;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -57,12 +61,6 @@ public class MainActivity extends AppCompatActivity {
         gridPieces = findViewById(R.id.gridPieces);
         mainImage = findViewById(R.id.mainImage);
 
-        // Setup Back Button
-        Button backBtn = findViewById(R.id.backToHomeBtn);
-        if (backBtn != null) {
-            backBtn.setOnClickListener(v -> showHome());
-        }
-
         // Copy assets to sd card if not founded
         copyAssetsIfEmpty();
         // Get data from sd card
@@ -74,6 +72,53 @@ public class MainActivity extends AppCompatActivity {
 
         // Initial cart visual sync
         CartViewHelper.updateCartView(cartList, this);
+
+        // Action bar
+        if (getSupportActionBar() != null) {
+            getSupportActionBar().setDisplayShowHomeEnabled(true);
+            getSupportActionBar().setTitle(" 🚲 Atelier du Pignon - Gestion du stock à prix libre");
+        }
+
+        // Get app version
+        String versionName;
+        try {
+            versionName = "App v" + getPackageManager().getPackageInfo(getPackageName(), 0).versionName;
+        } catch (Exception e) {
+            versionName = ""; // Fallback
+        }
+
+        // Launch server
+        server = new ControlServer(8080);
+        try {
+            server.start();
+            String url = "http://" + getDeviceIP() + ":8080";
+
+            // On met l'URL directement dans le sous-titre de l'ActionBar
+            if (getSupportActionBar() != null) {
+                getSupportActionBar().setSubtitle("Serveur en ligne : " + url + " - " + versionName);
+            }
+            Log.i(TAG, "Server started on : " + url);
+        } catch (IOException e) {
+            if (getSupportActionBar() != null) {
+                getSupportActionBar().setSubtitle("Erreur serveur" + " - " + versionName);
+            }
+        }
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        // Ensure cart is up to date if returning to the activity
+        CartViewHelper.updateCartView(cartList, this);
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        if (server != null) {
+            server.stop();
+            Log.i(TAG, "Server stopped.");
+        }
     }
 
     /**
@@ -149,6 +194,8 @@ public class MainActivity extends AppCompatActivity {
         homeLayout.setVisibility(View.GONE);
         categoryItemsLayout.setVisibility(View.VISIBLE);
 
+        updateActionButton(false);
+
         gridPieces.removeAllViews();
 
         // Calculate item width for a 4-column grid
@@ -215,9 +262,11 @@ public class MainActivity extends AppCompatActivity {
         CartViewHelper.updateCartView(cartList, this);
     }
 
-    private void showHome() {
+    public void showHome() {
         categoryItemsLayout.setVisibility(View.GONE);
         homeLayout.setVisibility(View.VISIBLE);
+
+        updateActionButton(true);
     }
 
     private void loadMainImage() {
@@ -225,8 +274,6 @@ public class MainActivity extends AppCompatActivity {
         ImageLoader.loadImage(mainImage, "_velo", 800,800);
     }
 
-    // --- Button Actions (linked via android:onClick in XML) ---
-
     public void emptyCart(View view) {
         CartActionHelper.emptyCart(cartList, this);
     }
@@ -235,36 +282,87 @@ public class MainActivity extends AppCompatActivity {
         CartActionHelper.validateCart(cartList, this);
     }
 
+    public void updateActionButton(boolean isHome) {
+        Button btn = findViewById(R.id.validateCartBtn);
+        if (btn == null) return;
+
+        if (isHome) {
+            // Home mode : validate button
+            btn.setText(getString(R.string.cart_validate_btn));
+            btn.setBackgroundColor(Color.parseColor("#43A047")); // Vert
+            btn.setOnClickListener(v -> validateCart(v));
+        } else {
+            // Category mode : back button
+            btn.setText(getString(R.string.cart_back_btn));
+            btn.setBackgroundColor(Color.parseColor("#1E88E5")); // Bleu
+            btn.setOnClickListener(v -> showHome());
+        }
+    }
+
     private int dpToPx(int dp) {
         return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, getResources().getDisplayMetrics());
     }
 
-    @Override
-    protected void onResume() {
-        super.onResume();
-        // Ensure cart is up to date if returning to the activity
-        CartViewHelper.updateCartView(cartList, this);
-    }
-
     private void copyAssetsIfEmpty() {
-        File folder = new File(Environment.getExternalStorageDirectory(), Config.EXTERNAL_DIR_NAME);
+        File rootDir = new File(Environment.getExternalStorageDirectory(), Config.EXTERNAL_DIR_NAME);
 
-        // First safety : is folder already in sdcard ?
+        // Create root folder if not found
-        if (!folder.exists()) {
+        if (!rootDir.exists()) {
-            // Second safety : are we able to create folder ?
+            if (!rootDir.mkdirs()) {
-            if (folder.mkdirs()) {
+                Log.e("MainActivity", "Can't create root dir." + rootDir.getAbsolutePath());
-                // Copy JSON file
+                return;
-                copyFileFromAssets(Config.PIECES_FILE_NAME, new File(folder, Config.PIECES_FILE_NAME));
-
-                // Copy images subfolder
-                File imgFolder = new File(folder, Config.IMAGES_SUBDIR_NAME);
-                if (imgFolder.mkdirs()) {
-                    copyFolderFromAssets(Config.IMAGES_SUBDIR_NAME, imgFolder);
             }
         }
+
+        // Check pieces.json
+        File inputJson = new File(rootDir, Config.INPUT_JSON_NAME);
+        if (!inputJson.exists()) {
+            Log.i("MainActivity", "pieces.json not found, copying it...");
+            copyFileFromAssets(Config.INPUT_JSON_NAME, inputJson);
+        } else {
+            Log.d("MainActivity", "Keep existing pieces.json");
+        }
+
+        // Check stock.json and stock.csv output files to avoid control server error
+        checkOrCreateEmptyFile(new File(rootDir, Config.OUTPUT_JSON_NAME), "[]");
+        checkOrCreateEmptyFile(new File(rootDir, Config.OUTPUT_CSV_NAME), "");
+
+        // Check images folder
+        File imgDir = new File(rootDir, Config.IMAGES_SUBDIR_NAME);
+        if (!imgDir.exists()) {
+            if (!imgDir.mkdirs()) {
+                Log.e("MainActivity", "Can't create images dir.");
+                return;
+            }
+        }
+
+        // Copy images only if not found
+        String[] filesInImgDir = imgDir.list();
+        if (filesInImgDir == null || filesInImgDir.length == 0) {
+            Log.i("MainActivity", "Images folder empty. Installing images...");
+            copyFolderFromAssets(Config.IMAGES_SUBDIR_NAME, imgDir);
+        } else {
+            Log.d("MainActivity", "Keep existing images.");
+        }
+    }
+
+    /**
+     * Create a file with default content if not found
+     */
+    private void checkOrCreateEmptyFile(File file, String defaultContent) {
+        if (!file.exists()) {
+            try (FileOutputStream fos = new FileOutputStream(file)) {
+                fos.write(defaultContent.getBytes());
+                Log.d(TAG, "Initialisation de : " + file.getName());
+            } catch (IOException e) {
+                Log.e(TAG, "Erreur lors de l'initialisation de " + file.getName(), e);
+            }
         }
     }
 
+    /**
+     * Copy folder from assets
+     */
     private void copyFolderFromAssets(String assetDirName, File destDir) {
         try {
             String[] files = getAssets().list(assetDirName);
@@ -280,25 +378,50 @@ public class MainActivity extends AppCompatActivity {
                 }
             }
         } catch (IOException e) {
-            Log.e("MainActivity", "Erreur listing assets: " + assetDirName, e);
+            Log.e("MainActivity", "Listing assets error: " + assetDirName, e);
         }
     }
 
+    /**
+     * Copy file from assets
+     */
     private void copyFileFromAssets(String assetName, File destFile) {
         // Optimized read
         // Try-with-resources ensures streams are automatically closed, avoid memory leaks
         try (InputStream in = getAssets().open(assetName);
              OutputStream out = new FileOutputStream(destFile)) {
 
-            byte[] buffer = new byte[1024];
+            byte[] buffer = new byte[8192];
             int read;
             while ((read = in.read(buffer)) != -1) {
                 out.write(buffer, 0, read);
             }
-            Log.d("MainActivity", "Succès : " + assetName + " copié.");
+            Log.d("MainActivity", "Success : " + assetName + " copied.");
 
         } catch (IOException e) {
-            Log.e("MainActivity", "Erreur copie asset: " + assetName, e);
+            Log.e("MainActivity", "Can't copy asset: " + assetName, e);
         }
     }
+
+    /**
+     * Get device IP to print it to users for easy remote control
+     */
+    private String getDeviceIP() {
+        try {
+            java.util.Enumeration<java.net.NetworkInterface> interfaces = java.net.NetworkInterface.getNetworkInterfaces();
+            while (interfaces.hasMoreElements()) {
+                java.net.NetworkInterface iface = interfaces.nextElement();
+                java.util.Enumeration<java.net.InetAddress> addresses = iface.getInetAddresses();
+                while (addresses.hasMoreElements()) {
+                    java.net.InetAddress addr = addresses.nextElement();
+                    if (!addr.isLoopbackAddress() && addr instanceof java.net.Inet4Address) {
+                        return addr.getHostAddress();
+                    }
+                }
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "IP error", e);
+        }
+        return "127.0.0.1";
+    }
 }

app/src/main/res/layout/activity_main.xml

@@ -42,12 +42,6 @@
             android:visibility="gone"
             android:padding="10dp">
 
-            <Button
-                android:id="@+id/backToHomeBtn"
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="← Retour" />
-
             <ScrollView
                 android:layout_width="match_parent"
                 android:layout_height="match_parent">

app/src/main/res/values-night/themes.xml

@@ -2,9 +2,9 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
 
     <style name="Theme.Pignon" parent="Theme.AppCompat.Light.DarkActionBar">
-        <item name="colorPrimary">@color/purple_500</item>
+        <item name="colorPrimary">@color/pignon_blue</item>
-        <item name="colorPrimaryDark">@color/purple_700</item>
+        <item name="colorPrimaryDark">@color/pignon_blue_dark</item>
-        <item name="colorAccent">@color/teal_200</item>
+        <item name="colorAccent">@color/pignon_blue</item>
     </style>
 
 </resources>

app/src/main/res/values/colors.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="purple_500">#FF6200EE</color>
+    <color name="pignon_blue">#0049AF</color>
-    <color name="purple_700">#FF3700B3</color>
+    <color name="pignon_blue_dark">#003580</color>
-    <color name="teal_200">#FF03DAC5</color>
+    <color name="white">#FFFFFF</color>
 </resources>

app/src/main/res/values/strings.xml

@@ -3,8 +3,9 @@
 
     <string name="cart_name">Mes sacoches</string>
     <string name="cart_validate_btn">Valider</string>
+    <string name="cart_back_btn">Retour</string>
     <string name="cart_empty_btn">Vider</string>
-    <string name="cart_empty">Sacoches vides</string>
+    <string name="cart_empty">C\'est vide !</string>
     <string name="cart_item">Quantité : %1$d (%2$d - %3$d €)</string>
 
     <string name="currency">€</string>
@@ -13,6 +14,6 @@
     <string name="popup_name">Mes sacoches</string>
     <string name="popup_item"><![CDATA[<b>%1$d x %2$s</b> : %3$d - %4$d €<br>]]></string>
     <string name="popup_total"><![CDATA[<br><b>Contribution consciente dans la petite boîte : %1$d - %2$d €</b>]]></string>
-    <string name="popup_end">Sacoches sauvegardées, merci !</string>
+    <string name="popup_end">Sacoches sauvegardées, merci ! ❤️</string>
 
 </resources>

app/src/main/res/values/themes.xml

@@ -2,11 +2,9 @@
 <resources xmlns:tools="http://schemas.android.com/tools">
 
     <style name="Theme.Pignon" parent="Theme.AppCompat.Light.DarkActionBar">
-        <item name="colorPrimary">@color/purple_500</item>
+        <item name="colorPrimary">@color/pignon_blue</item>
-        <item name="colorPrimaryDark">@color/purple_700</item>
+        <item name="colorPrimaryDark">@color/pignon_blue_dark</item>
-        <item name="colorAccent">@color/teal_200</item>
+        <item name="colorAccent">@color/pignon_blue</item>
-
-        <item name="actionBarSize">40dp</item>
     </style>
 
 </resources>